The present disclosure relates generally to operations performed and equipment utilized in conjunction with a subterranean well and, in particular, to a subsurface safety valve with a magnetic booster feature.
Subsurface safety valves are well known in the oil and gas industry and act as a failsafe to prevent the uncontrolled release of reservoir fluids in the event of a worst-case scenario surface disaster. Typical subsurface safety valves are flapper-type valves, which are opened and closed with the help of a flow tube moving telescopically within the production tubular. The flow tube is often controlled hydraulically from the surface and is forced into its open position using a piston and rod assembly that may be hydraulically charged via a control line linked directly to a hydraulic manifold or control panel at the well surface. When sufficient hydraulic pressure is conveyed to the subsurface safety valve via the control line, the piston and rod assembly forces the flow tube downwards, which compresses a spring and simultaneously pushes the flapper downwards to the open position. When the hydraulic pressure is removed from the control line, the spring pushes the flow tube back up, which allows the flapper to move into its closed position.
Some safety valves are arranged thousands of feet underground wherein the hydrostatic pressure can be thousands of pounds per square inch (psi). This may require the hydraulic pressure in the control line to exceed 10,000 psi, thus requiring expensive special high-pressure pumps and equipment.